Since its advent, the small and rugged semiconductor laser has found extensive use in applications that had been met only unsatisfactorily, or not at all, by the relatively bulky and more fragile Helium-Neon gas laser. Among these applications has been that of providing an aiming point in connection with the use of firearms: the laser diode and required drive circuitry and battery source are mounted on the firearm, and the direction of the laser beam is adjusted so that at some predetermined range, the dot of light produced by the laser beam is coincident at the point at which a bullet from a standard round of ammunition will impact when fired. The advantage of such an aiming system is that the operator need not look through any sights at all: if the laser beam has been appropriately aligned, a bullet will strike a target at the point identified by the laser dot, regardless of the manner in which the operator of the firearm may have been obliged to fire the weapon. For example, the operator may hold the weapon at arm's length, e.g., extending above some protective "cover," and view the target from a different vantage point than the location of the weapon itself, thereby avoiding exposure to any hostile fire from the targeted area. In addition, if a laser diode is used that emits infrared radiation, and if the operator is using night vision equipment that can "see" that infrared radiation, such laser aiming can occur without being detected by persons in the target area who do not also have night vision equipment.
One of the difficulties in achieving such a system, however, has been that of providing a stable and convenient mounting of the laser device to the firearm, and one that at the same time can be adjusted so that the laser dot will indeed coincide with the point of impact of a fired bullet at some preselected range. Secondly, since the module that contains the laser diode and drive circuitry, such as the "visible laser module" ("VLM.TM.") made by Applied Laser Systems, must be provided with a power source and a switch by which to control that power, it has been necessary to include external wires running to some type of switch that can be operated in conjunction with the trigger operation. Up to the present, the practice has been to provide a type of mounting structure within which the laser device can be mounted and adjusted in terms of orientation, and then to place that structure with its included laser module onto the firearm. A pair of leads runs from this structure to a momentary switch that is placed at a convenient point on the firearm. Aiming of the laser so that the beam spot coincides with the point of bullet impact at some desired range is then carried out by actual field tests.
Such a prior art structure is shown in FIG. 1, in which laser aimer 10 comprises a hollow laser body 12 and laser mount 14. The laser device itself (not shown) and a battery that powers the laser (also not shown) are contained within laser body 12. A knurled, screw-on cap 16 at an end of the laser body opposite the direction of laser beam 18 permits insertion of the battery. Laser body 12 includes, at the end from which laser beam 18 emerges, a portion 20 that has been expanded to accommodate the length of three alignment set screws 22 (of which just one is shown in FIG. 1) oriented at appropriate relative angles, with the inner ends of screws 22 touching an outer surface of the laser device. The inner diameter of laser body 12 is made sufficiently larger than the outer diameter of the laser device that by adjustment of the depth of penetration of screws 22 into laser body 12, the orientation of the laser device and hence of laser beam 18 relative to the longitudinal axis of laser body 12 can be adjusted. One disadvantage of this prior art system is that because of the close proximity of laser body 12 to the barrel on which it is to installed, at least one of screws 22 will be difficult to access. FIG. 1 also shows leads 24 which extend from screw-on cap 16 to momentary switch 26 for operation of power to the laser.
Several types of firearms, particularly rifles, include along the top surface thereof a .22 dovetail groove mount 28, for mounting a telescopic sight, as shown on the top surface of barrel 30 in FIG. 2. The cross-sectional structure of laser mount 14, shown in the isometric view of FIG. 2, is structured to slide onto groove mount 28, and upon being placed thereon laser mount 14 can be tightened onto groove mount 28 using mounting screws 32 that pass through laser mount 14. Once the laser device has been attached to the firearm in this manner, the orientation of laser beam 18 relative to the axis of the firearm itself (i.e., of the barrel) can be adjusted using set screws 22. For firearms that include groove mounts of different sizes than the .22 groove mount, such as the Weaver telescope mount, to avoid fabricating laser mount 14 in such various sizes an additional mounting adapter sized to adapt laser mount 14 to such a groove mount may be used. If the firearm has no groove mount at all, one must use some type of clamp, such as a "quick clamp," to attach the laser device to the firearm.
The principle disadvantage of such systems, especially when employed with a handgun such as a pistol or revolver, is the resultant bulk and awkward configuration. Handguns in particular are used most effectively, e.g., for law enforcement purposes, when they can be holstered. Standard holsters will not accommodate a firearm onto which a laser aimer has been mounted in the manner described (i.e., above the barrel), nor would such a firearm provide the usual level of convenience and utility even if a holster were fabricated for it. Also, lead wires that are external to the firearm can interfere with holstering of the weapon, and are also subject to wear or breakage. What is required and would be useful, therefore, is a method and apparatus for mounting a laser aimer onto a firearm that would eliminate such bulk and awkward configuration. It would also be useful to provide means for adjusting the orientation of the laser beam, and for turning on the laser beam, that are more integral to the firearm itself.